Protection of aldehydes from oxidation and agents therefor



Patented Nov. 19, 1929 HAROLD A. MORTON, OF AKRON, OHIO PROTECTION OF ALDEHYDES FROM OXIDATION AND' AGENTS THEREFOR No Drawing.

Considerable difliculty is experienced in the storage and handling of various aldehydes due to oxidation to the corresponding acids. This oxidation results in the contamination of the aldehyde with undersirable acids; in the destructive action of the acid on the containers; and in the discoloration of the product and accumulation of impurities due to the corrosive action of the acid on-the metal container.

My invention relates to the retardation or prevention-of the oxidation of aldehydes by the addition of a material possessing anti.- oxidant properties. 7

According to my invention, the aldehyde or aldehyde solution to be preserved has as an added ingredient a small quantity of 1-2 diamino ethane or a derivative thereof.

There are a number of such amino derivatives of ethane which function in this manner and they may be represented by the following general chemical constitution:

H, CH CHQCHQ, CHgCH CHg, (CHflzCH, CHaCHgCHgCHg, CH CH CH C-HaCHgCHgCHgCHg, (CH3) ZCHIIHgCHz, Ca s, gu s- 3, a M 921 o a 2, am a. o B an m 6 4 1 io 'I- R(a) R(b), R(e) and R(f) may also be any of the following chemical groups or their equivalents NO, C H (CH N0 C H NO C H Cl; but in the case of these more negative groups, not more than two should be used in each molecule.

Application filed July I4,

1928. Serial No. 292,909.

R(c) R(g) and R(h) ma be an of the folldwing bhemical radicals: y y

CH (311.011 c132,. tn15, cantons, CHHACHQZ, 010a,, Camilla; 2 2

In this specification all the materials re ferred 'to"are nitrogen derivatives of ethane. In general they may be prepared by heating the dihalogen derivative of ethane (or substituted ethanes) with the appropriate amino compound, although other methods of preparation may be employed.

By the term derivative, as used in this specification and claims, it is not intended to include molecular constitutions containin several strongly ne ative groups as pointed out above, nor do intend to include molecular constitutions containing still more highly negative groups such as CeH CO, C H (N0 CH G H (N0 etc.

The nomenclature used to denote the position of the substituted chemical groups is the conventional system, the structure of the iathane molecule being considered to be as folows:

n H nz s-(1) (J-H As examples of compounds of this class which have been found to have anti-oxidant properties, I may mention the followin HHHH NHOIO HHHHH (benzyl amino) ethane (butyl phenyl amino) ethane (phenyl amino) 2-methy1 ethane (ortho tolyl amino) 2-methy1 ethane (para tolyl amino) 2-methyl ethane (xyjyl amino) 2-methy1 ethane (alpha naphthyl amino) 2-methy1 ethane i (beta naphthyl amino) 2-methyl ethane (phenyl xylyl diamino) 2-methyl ethane i (ethyl phenyl amino 2-methy1 ethane (phenyl ortho tolyl' iamino) 2-methyl ethane (phenyl nitros amino) 2-methyl ethane (phenyl alpha naphthyl diamino) 2-methyl ethane (phenyl amino) 2-isopropyl ethane (phenyl amino) 2-pseudo butyl ethane (ethyl ortho tolyl amino) 2-methyl ethane (phenyl amino) 2-methy1 ethane (phenyl amino) 1-2-dimethy1 ethane (ortho tolyl amino) 1-2-dimethyl ethane (para tolyl amino) 1-2-dimethyl ethane (alpha naphthyl amino) 1-2-dimethyl ethane (ortho tolyl amino) 2-ethy1 ethane (phenyl amino) 2-2-dimethy1 ethane (phenyl amino) l-methyl 2-ethy1 ethane (phenyl amino) 1-2-diphenyl ethane (phenyl amino) 1-2-2-trimethyl ethane (ortho tolyl amino) 1-2-2-trimethy1 ethane (alpha naphthyl amino) 1-2-2-trimethy1 ethane (phenyl amino) 1-1-2-2-tetra-methyl ethane (ortho tolyl amino) 1-1-2-2-tetra-methy1 ethane v (alpha naphthyl. amino) 1-1-2-2-tetra-methyl ethane DID:

HHHHHHHHHHH NNNN The above examples are of value in practicing this invention and serve to indicate the wide range of materials of this type which are of value in preventing the oxidation of'aldehydes. However, they are given only as typical examples and this invention is not limited to these specific compounds.

For example, it is not only possible to use the free bases of the above series but the salts and soaps formed from these materials also exhibit substantially the same effect, the antioxidant properties apparently being in the diamino ethane portion of the radical.

The'amount of the material which is used may vary greatly, but quantities ranglng from 0.25% to 1.0% have been found to produce good results. Of course a smaller amount of material me be used if the preserving action need not e so great and correspondingly the quantity may be increased considerably above 1.0% if it seems desirable. In general the compounds of this invention are easily prepared and some member of the, group is soluble in each of the commonaldehydes. The activity of these materials is not destroyed by relatively high temperatures.

.In general these compounds impart no'undesirable characteristics to the aldehydes.

The process maybe used in any place where it is desirable to prevent the oxidation of aldehydes, whether this be during storage and handling or during the course of chemical reactions. p

The process of this invention may also be practiced with any material which contains wearer aldehyde groups and which has a tendency to become oxidized.

' To illustrate the manner in which the foregoing materials may be used and the effect which they have on the oxidation of aldehydes the following examples are given Ewample 1 A sample of butylaldehyde contained in a small flask equipped with a reflux condenser was treated with a comparatively rapid stream of dry oxygen at atmospheric temperaturel The same conditions were used in a series of other flasks containing butylaldehyde in the presence of 1-2 di (phenyl amino) ethane, (C H NHCH CH NHC H and the rate of oxidation determined by analyzing the butylaldehyde at regular intervals for the amount of butyric acid formed.

The difference in oxidation was also readily noted by the relative change in temperature. The butylaldehyde containing no anti-oxidant, developed considerable heat as oxidation progressed, whereas the butylaldehyde samples in the vpresence of 1-2 di (phenyl amino) ethane showed no appreciable increase in temperature.

The following table shows the anti-oxidant effect of various quanties of 1-2 di (phenyl" amino) ethane.

An analysis of the butylaldehyde before treatment with oxygen showed that it contained 0.8% butyric acid.

Time Control Hours acid 1-2 di (phenyl amino) ethane acid acid acid It is seen from the above figures that 1-2 (li (phenyl amino) ethane materially retards the oxidation of butylaldehyde.

Ewample' 2 Time Control NmomomNm cwm HomomNHcwm) Hours acid 1-2 diamino ethane 1-2 di (alpha naphthyl amino) ethane %acid %acid Anti-oxidant 1 hen- 1 amino 2- a t l Example 3 on 1f 1 cel i n b iigdn N)HC e 0 Y1 am emica ormua H To illustrate the use of 12 d1 (phenyl Acidity V rm. 2 3 amlno) ethane for preservatilon'of benzal' Anti-oxidant 1-2 (H (ortho tolyl amino) ethane dehyde, the followlng example is glven. g gg 5 g g mz ze i a u 0 Dry oxygen was passed through the A p ordmary temperature and the Ciaaaaa... aateaaraaaaa: benzoic acld content was determined at regul y 5.4 lar intervals. Anti-oxidant 1-2 di (x lyl amino) ethane 5 Chenilcalformula (CHs) NHCH CH NHCaHflCH 5 Acid ty 0.9% 5% Anti-oxidant 1 (phenyl amino) 2-(ortho tolyl amdi Chemicalformula cfinb h dii NHCH4CH3 Time Control (phgnyl Acidity E 2 2 Hours %acid 5 Anti-oxidant 1 (phenyl ammo) 2-(alpha naphthyl 0 %acid amino) ethane Chemicalformnla commicn cnzmicmm Acidity 1.1% 3 5, 22 3 Anti-oxidant 1 (para. tolyl amino) 2-(alpha. naph- 18 8.50 2.45 thyl amino) ethane 2.40 Chemicalformnla CHaCH4NHCH CH NHC H 36 2 35 Acldlty 2 1.7% t, 54 15.00 2.40

Anti-oxidant 1-2 d1 (ethyl ortho tolyl ammo) ethane Chemicalformula. CH3 eH4NC H5CHgCH2 LH5NCoH CH Acidity 0.6%

A analysls was also made on the Anti-oxidant 51-2 di (ethyl phenyl amino) ethane benzaldehyde before the test and the ung fgg 3 g g z m treated aldehyde was found to contain 2.35% A ti t 12 (r t I 1 i 9 h 1 120 o benzoic acid. n on an -et :1 nepara o y am no) -met It is thus seen from the above table that L2 g gfggi formula 3 i zg m fi a I u 0 d1 (phenyl amino) ethane under the above A d t 12 rth t l 2 th 1 conditions practically completely prevents Hm i 0 y the oxidation of benzaldehyde to benzoic acid. g g g 5 5 1 semNHwfiacmcnmnctmcm E l 4 Anti-oxidant 1-2 tglphenyl xylyl diamino) 2-methy1 e 8119 Chemicalformula CaH5NH(CHs)CH.CH NHC ,H (CH To show the wide range of materlals of the Acidity 0.5% above series which are of value 1n practicing Antioxidant 1-2 n (alpha naphthyl amino) 2-methn0 e an @1118 Invention, the folkwmg example 1s Chemicalformnla C1o 7NH-(8Ha)CH.CHgNHCmH iven. Acidity 1.2%

h rate of oxldatlon Is not} shownda't fi The above examples are illustrative of the lute/flak, y one F bemg ma 6 at 9 various methods of carrying out this invenend of a s1x hour period of treatmentwith tiom oxygen. It is to be noted that all of the mem- What I claim i beIS ShOW aQtl-oxldant P P S to Y ym 1. The method of retarding the oxidation degrees. It is thus possible for one skilled 111 of aldehydes which compnses addmg to the the art to choose the P p mammal for the aldehyde 1-2 diamlno ethane or a derivative purpose at hand. thereof.

1 l of h followmg cases of the 2. The method of retarding the oxidation ant-l-oxld 18 used of aldehydes which comprises addlng to the the Present example h control: Whlch aldehyde a derivative of 1-2 dlammo ethane, conslstfid I butylaldehyde 1n h absence of wherein one of the hydrogen atoms of each an anti-oxldant Showed ll fiy O amino group is replaced byanorganic radlcal. 1:3 butyric acld at the end of the SIX hour oxlda- 3, A a agent for retarding the oxidation tion period. of an aldehyde, 1-2 diamlno ethane or a derivative thereof.

Anti-oxidant 1-2 61 (phenyl amino) l-2-dimethyl g ethane 4. The method of retarding the oxidatlon iggtg j; of aldehydes WhlCh comprlses addlng to the aldehyde a derivative of 1-2 diamino ethane, wherein one of the hydrogen atoms of each amino group is replaced by an aromatic group.

5. The method of retarding the oxidation of aldehydes which comprises adding to the aldehyde a derivative of 1-2 diamino ethane, wherein both of the hydrogen atoms of each amino group are replaced by two organic groups, one of which is an aromatic radical.

6. The method of retarding the oxidation of aldehydes which comprises adding to the aldehyde the organic base made by heating one mol of 1-2 dihalogen ethane and more than two mols of an aromatic amine.-

7. The method of retarding the oxidation of aldehydes which comprises adding to the aldehyde a di-aryl substituted 1-2 diamino ethane.

8. The method of retarding the oxidation of aldehydes which comprises adding to the aldehyde a derivative of a di-aryl substituted 1-2 diamino ethane.

9. The method of retarding the oxidation of aldehydes which comprises adding to the aldehyde 1-2 di (phenyl amino) ethane.

10. A compound containing a -CH() group to which has been added 1-2 diamino ethane, or a derivative thereof.

11. The method of retarding the oxidation of aldehydes which comprises adding to the aldehyde a derivative of 1-2 diamino ethane, wherein one of the hydrogen atoms of each amino group is replaced by a phenyl group.

12. The method of retarding the oxidation of aldehydes which comprises adding to the aldehyde a derivative of 1-2 diamino ethane, I

wherein both of the hydrogen atoms of each amino group are replaced by two phenyl groups.

In testimony whereof I aflix my signature.

HAROLD A. MORTON. 

